Computer system, deployment plan generation method, and deployment control system

A computer system is coupled to infrastructure systems each configured to implement an environment for providing resources to each of instances forming an application. The computer system is configured to: receive a deployment plan generation request for the application which includes a serverless instance for which, as an activation method, any one of a warm start and a cold start is selectable; generate, based on a resource amount required for the each of instances, an allocation pattern which is a combination of an environment of a deployment destination of the each of instances; generate an activation pattern which is a combination of the activation method for the each of instances; plan an activation timing of the serverless instance for the activation pattern; generate a plurality of deployment plans by combining the allocation pattern, the activation pattern, and the activation timing.